For me it's a bit different. My father died when I was young, so I was basically raised by a single mother. What makes it different is that my fetish basically grew out of frustration than anything else. My mom is from the beginning very conservative, and then after dad passed away, she didn't date anyone, ANYONE, seriously at all. Can you imagine how frustrating it is for a teenage boy not to be able to see the hottest woman in his life in any remotely sexual position ever? No accidental nudity, no peeking on her having sex, no nothing.

 I guess that's why most of my fantasies involve my mom being raped by strangers. Because I cannot even imagine my mom in consensual sex.